With regard to blogging about New Old Stock tubes, I have certainly been on a roll lately (pun intended). This Blog is about the Gec A2900s and Siemens & Halske E81CCs which in my opinion, represent unparalleled performance for Music Lovers with 12AT7 tubes in their circuits. In my humble opinion, I believe I have discovered my "Holy Grail" combination of 12AT7 signal tubes for my VTL amplifier. I recently blogged about the rare Telefunken Long Plate 5965 that ostensibly can substitute for the 12AT7 even though it draws more heater current than the 12AT7. For anyone who may be concerned about this extra heater current draw, the GEC A2900 Long Black Plates provide the same Lively, 3D, and Open sound that I experienced with the Telefunken 5965's. The difference is the Gec A2900s provide a level of musicality that must be heard in order to be believed. The following review comments of the Gec A2900 and the Siemens & Halske E81CC is after 50 hours of burn-in for the A2900s and over 100 hours for the E81CCs.
With the Telefunken 5965, I was using NOS Siemens ( not Siemens & Halske ) 801s for the input and the Telefunken 5965 for the drivers. As good as this combination sounded, I felt that the musicality of the presentation was somewhat wanting. I analytically view Resolution as a vector that is equal to the sum of the vectors Musicality and Accuracy ( R= M+A ). Hence, the greater the Resolution in ones High-End Audio System, the greater the Musicality and Accuracy. Using this equation helps one to maximize their existing tube component's performance via tube rolling and finding their perfect synergy with regard to Accuracy and Musicality.
The NOS West German tubes all deliver exemplary accuracy. However, I demand authority and a full bodied sound with this accuracy. In my opinion, the Valvo's, Siemens (not Siemens & Halske ), and Telefunkens are accurate as hell but a bit thin sounding. I found what I wanted in a pair of Siemens & Halske E81CCs. These are now my Reference input signal tubes in my VTL amp replacing the 801s. My search for the driver tubes that would deliver the level of musicality I've been seeking from the quintessential accuracy of the Siemens & Halske E81CC that feed my driver tubes ended with my purchase of the Gec A2900 tubes from Joshua Syna at Tejas tubes. http://www.tejastubes.com/
My system consists of the following: A refurbished Thorens 126 MKIII with a Denon 103r, A KAB modified Technics SL-1210 with separate power supply with a Denon 103. Both of my analog front-ends utilize an Allnic AUT 2000 Step Up Transformer. My Digital front-end is a Proceed CDD Transport that feeds a modified Monarchy NM24 DAC using Siemens & Halske 6922s that is powered by a Monarchy AC Regenerator that I set to 120 Hz. My Preamp is a restored Harman Kardon Citation 1 with NOS Telefunken Ribbed Plate 12AX7s in the V1, V2, V6, and V7 positions which are the Phono Stage tubes. V1 and V6 drive the RIAA network and V2 and V7 amplify and buffer the RIAA output. I use Nos Mullard 10M tubes in the V3 and V8 positions which are the inputs for the Line stage and NOS Mullard CV4024 tubes in the V4 and V9 positions which are line amps and anode followers for the output. My Power amp is a restored VTL Stereo 90 Deluxe Ultra-Linear. My Speakers are JMlab Focal Utopia Diva Be. All cabling is by Donald Smith of Sound Design Labs. http://sounddesignlabs.org/
With the Gec A2900s in my VTL, the musical presentation relinquishes all compromises. The entire frequency range is in my opinion, exactly the way it should be heard. With this level of perfection one experiences a more profound insight and a greater emotional connection to the recorded event. The Gec A2900s in my system provide a level of realism I have never experienced before and has given me a whole new perspective with regard to "Enjoy the Music". In addition, this tube's high gain allows you to feel more of the music. The Sound stage is widened in all dimensions and with the heightened detail, provides the most realistic sense of the venue of the recorded event I have ever experienced.
In conclusion, the Gec A2900s are simply incredible. In my opinion, the Gec A2900s are unequivocally the best 12AT7s in the world. They take total control of your Power tubes ( I'm using Ge 6550a tubes ) which provides you greater headroom and output performance which is why I highly recommend the A2900s in the signal tube driver position of your amp. They demonstrate an unbelievably musical, balanced, dead quiet, smooth, and detailed presentation. They take the highly accurate signal from my E81CC's and impart a musical warmth that is undeniably "MAGICAL". The German Siemens & Halske E81CC's accuracy combined with British Gec A2900's musicality deliver the consummate Resolution I've inexorably been trying to achieve since I've been in high-end audio. Inserting Sound Design Labs' Reference AE Joule Case Power Conditioner in your system is the only way it gets any better than this!!!!